Length of DVD: Just over 70 minutes, but you could just follow one of the 20-minute workouts at a time. It’s suggested you do one of the workouts, four times a week.

What do we need to know?: Josie looks amazing after losing four stone and dropping from a size 20 to a 10 – and she’s putting it all this down to the gorgeous James and his intense activity interval training workout.

The DVD, which is apparently out-selling veteran Davina McCall’s, has three 20-minute workouts in different levels, from beginner to advanced. The workout includes 30 seconds of intense activity followed by active rest, which can mean walking, stretching or jogging. James demonstrates each exercise, while Josie presents a slightly easier version.

Who’s it aimed at?: People short on time.

Clarity of instructions: Very clear. Straightforward and easy to follow. The only equipment needed is a pair of dumbbells, but you could use small bottles of water or tinned beans. And if you can’t keep up with James, you can follow Josie.

Likeability of instructor: James and Josie work really well together and both are likeable. James is very clear and encouraging – and did I mention he’s gorgeous?

Best bit: The very easy-to-follow Walking Up Down. You place your hands on the mat and walk out, then walk back in and have a big stretch to the right, then left. I also enjoyed the Kick Through – jog on the spot and then kick through with alternate legs.

Worst bit: Squat Thrust, a deep press up and then jump in and out with your legs.

I’m recovering from a knee injury and it was the most difficult to do.

Difficulty rating: 7/10.

Results: I certainly felt it the next day in my legs and arms. Josie is a great ambassador for the programme and by working up to the top level, you can see how it would work. The fact it only takes 20 minutes, means it’s easy to fit into a busy lifestyle, so four times a week seems enough.

Who?: Presenter Davina McCall is no stranger to the fitness DVD, having sold 1.5 million DVDs in eight years. She’s back with personal trainers, Jackie and Mark Wren, on her ninth installment.

Length of DVD: 95 minutes.

What do we need to know?: Split into five sections – warm up, intense cardio box, intense toning, intense abs and cool down, the idea is to keep you at an intense level of exercising, with your heart rate up for a period of time before having a rest period, then another intense level of exercise.

There are two-minute breaks between each workout, allowing you to get your heart rate to drop again and take some much needed water breaks.

Who’s it aimed at?: Anyone serious about getting/staying fit. There’s no easy part, in the sense that it’s pretty full on from the word go. But I’d say this is pretty much for everyone if you like high-energy routines.

Being fun, with Davina’s usual dizzy banter, I even roped my 12-year-old son into joining in.

Clarity of instructions: Good. But, in the introduction, Davina recommends doing three to four workouts a week and to mix it up.

I wouldn’t attempt to do the entire DVD in one go, not if you wish to walk the following day, but I found over a period of time and with the intense nature of the workouts, my stamina improved and my recovery time dropped, so felt I was really improving my fitness levels week on week.

Likeability of instructor: She’s like Marmite, but I found Davina, with her impressive six pack and array of brightly coloured gym wear along with her regular face pulling at Mark and Jackie, rather entertaining.

It also distracted me from some of the burn.

Best bit: Either the Intense Cardio Box (squats, lunges, running on the spot, at a very fast pace) – I found this quite difficult on my first few attempts as I’m not the most coordinated person, but once I got familiar with the routine, settled into it well.

Or, the Intense Abs. A much shorter section thankfully after the previous two, this is a really good abs section starting with some standing ab work followed by floor work.

I really felt the results of this section whenever I did it, be it on its own or with the other sections.

I always find it satisfying to feel the pull and ache the following day as I know I’m working hard to achieve that washboard stomach.

Worst bit: The Intense Toning section.

Again, a very fast routine but with slightly longer rest periods between the exercises.

In this section comes the dreaded star jumps. Being someone who needs a super firm sports bra – this isn’t one of my favourite exercises.

Difficulty rating: 8/10. It’s easy to follow, with uncomplicated moves, and Mark or Jackie explain the next routine during breaks – giving you an early heads up of what to expect next.

But it’s hard to complete. Expect to be out of breath very quickly and don’t expect an easy ride, it is what it says – intense.

Results: This is a workout full of short bursts of fast, high-energy exercises that really gets your heart rate up.

A great all-round DVD for building stamina, core strength and fat burning, I was left exhausted and you really do get out what you put in.

Based on the principle of high intensity training, working out for a shorter length of time at a higher intensity, I found it great for stamina and fat burning.

Who?: American foghorn-voiced personal trainer and reality show personality. If you’ve seen Michaels bellow at the feckless slimmers on TV show The Biggest Loser USA, then you have some idea of what’s in store.

Length of DVD: There are 15 DVDS altogether and each workout is 30 minutes, while the programme works six days out of seven.

Half an hour a day isn’t too bad – but day after day does get quite gruelling after a while.

What do we need to know?: The DVDs take you through the three phases – four metabolic training workouts and one cardiovascular exercise workout per 30 days – as well as a complete book of pick ’n’ mix recipes, a workout calendar and a diet journal.

There’s also a resistance band which they use in some of the exercises.

The ethos is based on HIIT – high impact interval training – so the cardio slots are a minute each and the whole thing is very fast-moving, which made me feel a bit queasy first thing in the morning.

This is a definitive plan – lasting 90 days – to create your “best-ever body”, with diet and fitness covered.

There’s a week-long “kick-start your metabolism” plan of twice-a-day exercise and calorie-controlled meals before 12 further weeks of intensive training.

Who’s it aimed at?: The metabolic training workouts are designed to try one set of muscles one day, and then a different set the next, giving the body the proper time to rest between sessions.

Michaels refers to it as an “extreme weightloss programme”, so it could be used as a bootcamp for anyone wanting to get in shape.

A word of warning – it starts out quite gently, but throughout the weeks it gets tougher and tougher. Be prepared for a relentless going-over and the very real possibility of feeling like you’re going to be sick.

Clarity of instructions: It’s so clear – workouts are all set out in the fitness programme so you know exactly what you’re doing and when, and the recipes are easy to follow.

The only problem is that they’re written in American, leaving the average Brit scratching their head at measurements in “cups”. I used Google a lot to check the quantities.

Likeability of instructor: I like her because she makes me want to succeed – but it’s not an easy relationship.

If you find her jokes about making you pass out – “it wouldn’t be the first time!” or pretending to rap a bit annoying, then you’ll have trouble getting to grips with the exercises while she prattles on.

It’s also suitably cheesy, and Michaels is like a drill sergeant having a bad day, barking directions throughout, as well as some positive aphorisms.

The best one is probably, “If you have a ‘why’, you can tolerate any ‘how’”. How’s that for motivational?

Worst bit: Not necessarily the worst, but the more scary bit is the cardio.

From jumping lunges and skaters to “suicides” – essentially running really fast from one end of the room to another.

Difficult rating: 7/10.

The exercises are clear to follow, but they become more taxing fitness-wise as the DVD goes on.

Results: The plain diet gets a bit wearing quite quickly. But I lost 2lb in the first week and the toning exercises definitely work, especially on the stomach and arms. Is it worth the £99.99? At just over £1 a day, I’d say so.

Who?: Gareth Thomas and his Celebrity Big Brother housemates (The Only Way is Essex’s) Kirk Norcross and former glamour model, Nicola McLean. There’s also an appearance from Hollywood actor Mickey Rourke and the whole thing’s filmed at the Sugar Hut in Essex (TOWIE fans will be familiar), Malibu Beach, Beverley Hills and Hollywood.

Length of DVD: 78 minutes.

What do we need to know?: Former rugby star Gareth appears alongside Welsh fitness trainer Nikki O’Connell, taking us through seven easy-to-follow (but not necessarily easy-to-do) exercises that can be done in 10 to 15 minutes – so the idea is there’s no excuse to say you haven’t got time to keep fit.

You can do as many or as little as you like, but I certainly felt like I’d had a good workout after only one or two. Even Gareth sweats a lot throughout, which made me feel better as it proved it must have been working – and I wasn’t alone.

I did some of the exercises while the kids were at home and they ended up joining in, and absolutely loved it, so I’d say anyone in the family can do it.

Clarity of instructions: Very good and easy-to-follow.

Nikki takes viewers through every move and explains what position your body should be in, also giving easier and more difficult options depending on your experience. Gareth doesn’t say too much, but sweats an awful lot.

Likeability of instructor: Nikki is really good and it’s amazing to see how Gareth gets on with the moves. He is obviously very fit and that made me want to work harder. He also concentrates really well and doesn’t chatter all the way through, which I liked.

Best bit: I loved the body conditioning. This is designed as an all-over body workout and works on each part of the body to help tone. It had sidesteps and lots and lots of squats and they say a dumbbell is required but I used a couple of soup tins. It lasted about 13 minutes and I really did feel like I was having a whole body workout at different paces. I certainly felt the burn of lactic acid and enjoyed the exercises. Other sections include a high level cardio boot camp, a really great fat burner with plenty of marching, squats, jumping jacks and spotty dogs, and a tough 11-minutes of interval training.

Worst bit: The Upper Body Blast as, despite playing a lot of tennis, I don’t feel I have a lot of strength in my upper arms.

It’s given only a difficulty rating of 3/5 and, at first, appears quite tame but as the exercises went on, it got harder and harder.

It was very intense and I was put off by Nicola McLean, who didn’t seem to work up a sweat at all.

Difficulty rating: 7/10. Many exercises start off very easy and get progressively more difficult.

Results: As a busy working mum-of-two, this is the perfect DVD for fitting into hectic schedules.

I’m still the same dress size, but I’ve certainly toned up since I’ve been doing it and when I was able to do a couple of the programmes together, rather than just one, I did reap the benefits.

I’ve definitely worked off the Christmas excess, my tummy is tighter, and, despite my reluctance at doing any upper arm body work, I have muscles now that I haven’t seen for ages. I’d definitely recommend it.

Who?: They describe themselves as “world-class athletes, celebrity personal trainers and one of the UK’s leading fitness celebrity couples”. No, I’d never heard of them either. But I can’t fault their workout. And a Google search finds they’re Enigma and Doom from Sky One’s Gladiators; and a real-life, super fit couple.

Length of DVD: Each DVD is 115 minutes each. Both have an introduction, three 15-minute workouts, and nutritional advice at the end.

What do we need to know? The Fat Burning DVD has a sofa circuit, where you use the arm of your sofa to do moves such as press ups, sit ups and planks, a body blast workout on the mats, and a buddy up training workout, where you pair up with a partner to perform moves. The second, Body Sculpting, has a swiss ball workout, a core control workout and a strength training workout.

Jenny and Wayne are professional, explaining the moves well, and the importance of combining regular workouts with a healthy diet for the best body possible.

Who’s it aimed at?: Beginners through to advanced: Jenny performs a standard move while Wayne performs an advanced version for those who want more of a challenge.

Clarity of instructions: If you haven’t been to a fitness class in a while, you might not know some of the moves. I recommend watching each workout through at least once to familiarise yourself with the moves beforehand.

Likeability of instructor: Likeable, if a bit serious. No Davina-style banter here. But it it’s obvious they’re professionals and take their job seriously, which is inspiring.

Best bit: The sofa circuit plank. It seems so much easier to hold your body weight in a “about to do a press-up stance” when you’re holding onto the side of a sofa, as opposed to on the floor.

WalesOnline is part of Media Wales, publisher of the Western Mail, South Wales Echo, Wales on Sunday and the seven Celtic weekly titles, offering you unique access to our audience across Wales online and in print.